1. Field of the Invention
The present invention relates to a device for reading bar codes on a photographic film which is capable of identifying the numbers and the positions of image frames by reading the bar codes affixed to the image frames.
2. Description of the Related Art
In a photographic printing apparatus, a photographic film such as a negative or positive film is mounted on a negative carrier. This carrier together with the photographic film is disposed at a printing position in a printing apparatus body for printing. The long negative mounted on the negative carrier is conveyed in the longitudinal direction thereof by a conveying device mounted on the negative carrier so that the image frames can be sequentially located at the printing position for printing.
Bar codes are affixed to the individual image frames at the same positions relative to the individual image frames. An image frame is selected for printing by reading the bar code affixed to the image frame by a sensor, the selected image frame being automatically positioned at the printing position using a notch formed in correspondence with each of the image frames. The bar codes correspond to the frame numbers which are assigned to the frames in a predetermined order in the longitudinal direction of a negative. This enables the bar code corresponding to a desired frame number to be retrieved by inputting the frame number by an operator therefore, it is possible to facilitate the positioning of desired image frames even when printing of the image frames is performed discontinuously for reprinting or making additional copies.
However, figures representing image frame numbers or the name of a film maker may also be provided on a negative at positions which form the same locus as that of the bar codes. In consequence, the sensor may erroneously read the figures or the letters as bar codes. This leads to a misalignment of a desired image frame or an erroneous detection of a desired bar code. This problem can be solved if other symbols or figures are provided at positions at which the locus thereof does not coincide with that of the bar codes. However, it is impossible to ensure sufficient space for these symbols and figures because the portion of the negative,other than the image frames, is small.